FRATERNITY BROTHERS: Kenny Smith, speaking at Archbishop Molloy coach Jack Curran’s funeral this month, is following the career of Louisville’s Russ Smith, a fellow disciple of Curran. Photo: AP

FRATERNITY BROTHERS: Kenny Smith, speaking at Archbishop Molloy coach Jack Curran’s funeral this month (top), is following the career of Louisville’s Russ Smith, a fellow disciple of Curran. (
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When you’re a member of the fraternity, one of the late Jack Curran’s boys, you keep an eye out for each other.

For the last three years, as former Archbishop Molloy guard Russ Smith has matured from an undersized, unpredictable guard into an NCAA Tournament force for Louisville, former Molloy, North Carolina and NBA star turned TV analyst Kenny Smith has had his back.

“I talked about Russ Smith all the time, whenever I would speak to Coach Curran,’’ Kenny Smith told The Post. “Every time I would talk to Coach, he would tell me about Russ — how he’s doing, what he still needs to work on. I’ve only spoken to Russ once, that was last season, but I know him. He’s a Molloy guy, so I know him.’’

The nation is starting to know Brooklyn’s Russ Smith as well. He tore up the second- and third-round games in Lexington this weekend, averaging 25 points on 17-of-31 shooting from the field, 5-of-11 on 3’s.

Perhaps more than his offense, it is Smith’s frantic defense at the front of Louisville’s full-court trap that breaks opponents’ spirits. He had 10 steals in the two wins. Kenny Smith, a Queens native, has seen tremendous growth in the Louisville guard’s game.

“I think efficiency is the first thing that comes to mind,’’ said Kenny Smith. “He’s a lot more efficient. That comes with maturity. There’s no wasted dribbling, no wasted movement.

“Last year, there were times he forced things. This year, he’s forcing defenses to make decisions.’’

Russ Smith seemed stunned to hear another Molloy star from another generation was following his career so closely.

“I would say to him, ‘Thank you, I really appreciate it,’ ” he said. “I know so much about him. He’s a legend who came out of Lefrak City, starred at North Carolina, one of the great programs, played for the Rockets.

“I’ve watched his career. I know he’s on TNT now, something I’d like to do. I really look up to him.’’

Russ Smith knows there is humor in saying he looks up to Smith. When Louisville coach Rick Pitino first saw Russ at his summer camp, he had zero interest in the 5-foot-10, 140-pound fast-twitch water bug.

But Ralph Willard, another New York guy and a Pitino assistant, said he saw something in Smith.

But Willard kept pushing. Curran advised Smith to do a year of prep school to get bigger and stronger. Smith grew to 6-1 and added about 20 pounds. Pitino remained suspect at best. Until Smith sold himself.

“He lied to me,” Pitino said. “He named all these schools that were recruiting him, made up schools. … I said, ‘Now tell me the truth, you don’t have a scholarship, do you?’ ‘Oh, kind of not really, Coach.’ ”

Now Smith might be the most influential force left in this tournament. He’s a penetrator, a scorer, a distributor, a disrupter and after lighting Rupp Arena on fire over the weekend, he got a new Twitter handle, “RussArena.”

Now it’s on to another arena. The No. 1-seeded Cards (31-5) will face Oregon Friday (7:15 p.m.; CBS) at Lucas Oil Stadium in Indianapolis with a spot in the Elite Eight at stake.

Kenny Smith said he’d advise Russ to avoid thinking about being four wins away from a national title.

“I wasn’t fortunate enough to win an NCAA title, but I won two NBA titles and if it was Game 2, I wasn’t thinking about Game 5,’’ said Kenny. “My mind was on Game 2 and nothing else. It’s the only way you can be successful.’’

Russ said he’s taking the same approach. But when asked whether the Cards, who won their first two games by an average of 28.5 points, can lose if they play their ‘A+’ game and another team plays its ‘A+’ game, he had a ready response.

“The competitor in me says, ‘No,’ ’’ said Russ Smith. “But you learned certain things from Coach Curran from Day 1 — focus on the task at hand.’’